scsi: ufs: qcom: Add quirks for Samsung UFS devices

Introduce quirks for Samsung UFS devices to adjust PA TX HSG1 sync
length and TX_HS_EQUALIZER settings on the Qualcomm UFS Host
controller. This ensures proper functionality of Samsung UFS devices
with the Qualcomm UFS Host controller.

Signed-off-by: Manish Pandey <quic_mapa@quicinc.com>
Link: https://lore.kernel.org/r/20250411121630.21330-2-quic_mapa@quicinc.com
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/ufs/host/ufs-qcom.c

@@ -33,6 +33,10 @@
 	((((c) >> 16) & MCQ_QCFGPTR_MASK) * MCQ_QCFGPTR_UNIT)
 #define MCQ_QCFG_SIZE	0x40
 
+/* De-emphasis for gear-5 */
+#define DEEMPHASIS_3_5_dB	0x04
+#define NO_DEEMPHASIS		0x0
+
 enum {
 	TSTBUS_UAWM,
 	TSTBUS_UARM,
@@ -795,6 +799,23 @@ static int ufs_qcom_icc_update_bw(struct ufs_qcom_host *host)
 	return ufs_qcom_icc_set_bw(host, bw_table.mem_bw, bw_table.cfg_bw);
 }
 
+static void ufs_qcom_set_tx_hs_equalizer(struct ufs_hba *hba, u32 gear, u32 tx_lanes)
+{
+	u32 equalizer_val;
+	int ret, i;
+
+	/* Determine the equalizer value based on the gear */
+	equalizer_val = (gear == 5) ? DEEMPHASIS_3_5_dB : NO_DEEMPHASIS;
+
+	for (i = 0; i < tx_lanes; i++) {
+		ret = ufshcd_dme_set(hba, UIC_ARG_MIB_SEL(TX_HS_EQUALIZER, i),
+				     equalizer_val);
+		if (ret)
+			dev_err(hba->dev, "%s: failed equalizer lane %d\n",
+				__func__, i);
+	}
+}
+
 static int ufs_qcom_pwr_change_notify(struct ufs_hba *hba,
 				enum ufs_notify_change_status status,
 				const struct ufs_pa_layer_attr *dev_max_params,
@@ -846,6 +867,11 @@ static int ufs_qcom_pwr_change_notify(struct ufs_hba *hba,
 						dev_req_params->gear_tx,
 						PA_INITIAL_ADAPT);
 		}
+
+		if (hba->dev_quirks & UFS_DEVICE_QUIRK_PA_TX_DEEMPHASIS_TUNING)
+			ufs_qcom_set_tx_hs_equalizer(hba,
+					dev_req_params->gear_tx, dev_req_params->lane_tx);
+
 		break;
 	case POST_CHANGE:
 		if (ufs_qcom_cfg_timers(hba, false)) {
@@ -893,13 +919,26 @@ static int ufs_qcom_quirk_host_pa_saveconfigtime(struct ufs_hba *hba)
 			    (pa_vs_config_reg1 | (1 << 12)));
 }
 
+static void ufs_qcom_override_pa_tx_hsg1_sync_len(struct ufs_hba *hba)
+{
+	int err;
+
+	err = ufshcd_dme_peer_set(hba, UIC_ARG_MIB(PA_TX_HSG1_SYNC_LENGTH),
+				  PA_TX_HSG1_SYNC_LENGTH_VAL);
+	if (err)
+		dev_err(hba->dev, "Failed (%d) set PA_TX_HSG1_SYNC_LENGTH\n", err);
+}
+
 static int ufs_qcom_apply_dev_quirks(struct ufs_hba *hba)
 {
 	int err = 0;
 
 	if (hba->dev_quirks & UFS_DEVICE_QUIRK_HOST_PA_SAVECONFIGTIME)
 		err = ufs_qcom_quirk_host_pa_saveconfigtime(hba);
 
+	if (hba->dev_quirks & UFS_DEVICE_QUIRK_PA_TX_HSG1_SYNC_LENGTH)
+		ufs_qcom_override_pa_tx_hsg1_sync_len(hba);
+
 	return err;
 }
 
@@ -914,6 +953,10 @@ static struct ufs_dev_quirk ufs_qcom_dev_fixups[] = {
 	{ .wmanufacturerid = UFS_VENDOR_WDC,
 	  .model = UFS_ANY_MODEL,
 	  .quirk = UFS_DEVICE_QUIRK_HOST_PA_TACTIVATE },
+	{ .wmanufacturerid = UFS_VENDOR_SAMSUNG,
+	  .model = UFS_ANY_MODEL,
+	  .quirk = UFS_DEVICE_QUIRK_PA_TX_HSG1_SYNC_LENGTH |
+		   UFS_DEVICE_QUIRK_PA_TX_DEEMPHASIS_TUNING },
 	{}
 };
 

drivers/ufs/host/ufs-qcom.h

@@ -122,8 +122,11 @@ enum {
 				 TMRLUT_HW_CGC_EN | OCSC_HW_CGC_EN)
 
 /* QUniPro Vendor specific attributes */
+#define PA_TX_HSG1_SYNC_LENGTH	0x1552
 #define PA_VS_CONFIG_REG1	0x9000
 #define DME_VS_CORE_CLK_CTRL	0xD002
+#define TX_HS_EQUALIZER		0x0037
+
 /* bit and mask definitions for DME_VS_CORE_CLK_CTRL attribute */
 #define CLK_1US_CYCLES_MASK_V4				GENMASK(27, 16)
 #define CLK_1US_CYCLES_MASK				GENMASK(7, 0)
@@ -141,6 +144,21 @@ enum {
 #define UNIPRO_CORE_CLK_FREQ_201_5_MHZ         202
 #define UNIPRO_CORE_CLK_FREQ_403_MHZ           403
 
+/* TX_HSG1_SYNC_LENGTH attr value */
+#define PA_TX_HSG1_SYNC_LENGTH_VAL	0x4A
+
+/*
+ * Some ufs device vendors need a different TSync length.
+ * Enable this quirk to give an additional TX_HS_SYNC_LENGTH.
+ */
+#define UFS_DEVICE_QUIRK_PA_TX_HSG1_SYNC_LENGTH		BIT(16)
+
+/*
+ * Some ufs device vendors need a different Deemphasis setting.
+ * Enable this quirk to tune TX Deemphasis parameters.
+ */
+#define UFS_DEVICE_QUIRK_PA_TX_DEEMPHASIS_TUNING	BIT(17)
+
 /* ICE allocator type to share AES engines among TX stream and RX stream */
 #define ICE_ALLOCATOR_TYPE 2